Shearing device for circular knitting machines

ABSTRACT

TO PRODUCE A LONGITUDINAL CUT IN KNIT FABRIC DURING THE KNITTING THEREOF ON A CIRCULAR KNITTING MACHINE, A SHEARING DEVICE IN THE FORM OF SCISSORS OR AN ELECTRICAL RESISTANCE IS DISPOSED WITHIN THE NEEDLE CYLINDER OF THE   MACHINE. THE SHEARING DEVICE IS MOVABLE BETWEEN AN OPERATIVE POSITION IN WHICH THE FABRIC IS CUT AND AN INOPERATIVE POSITION.

SHEARINE DEVICE ECR CIRCULAR KNITTING MACHINES A. MAZZI 3 Sheets-Sheet lFeb. 6, 1973 Filed Aug. 5,

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3 y INMJ fafa/w BTTORUEYS United States Patent O 3,714,800 SHEARINGDEVICE FOR CIRCULAR KNITIING MACHINES Aramis Mazzi, Florence, Italy,assigner to Solis 3.121., Tavarmuzze, Florence, Italy Filed Aug. 5,1969, Ser. No. 847,615 Claims priority, application Italy, Ang. 14,1968, 841,972/ 68 Int. Cl. D04h 35/00 U.S. Cl. 66-147 6 Claims ABSTRACTOF THE DISCLOSURE To produce a longitudinal cut in knit fabric duringthe knitting thereof on a circular knitting machine, a shearing devicein the form of scissors or an electrical resistance is disposed withinthe needle cylinder of the machine. The shearing device is movablebetween an operative position in which the fabric is cut and aninoperative position.

BACKGROUND OF THE INVENTION This invention relates to a shearing devicefor circular knitting machines.

SUMMARY OF THE INVENTION According to the present invention there isprovided a shearing device for use in a circular knitting machine, saiddevice being capable of producing a longitudinal cut in knit fabricduring the knitting thereof on said machine, said device comprisingsupport means secured below the platen for the hooks and having alateral opening therein facing the needle cylinder at a position atwhich the cut is to be formed, shearing means mounted on the supportmeans and means operable to move the shearing means through the saidlateral opening between an inoperative position within the support meansand an operative position at which the cut in the knit fabric is formed.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will now be described,by way of example, with reference to the accompanying drawing, in which:

FIG. 1 is a longitudinal section 0f a shearing device in accordance withthe invention mounted on a circular hosiery knitting machine and shownin the operational configuration;

FIG. 2 is similar to FIG. l but shows the device when in-operative;

FIG. 3 illustrates a modification wherein the actual shearing member isan electrical resistance;

FIG. 4 illustrates a detail of a part shown in FIG. 3; and

FIG. 5 is a section on the line V-V of FIG. 4.

Referring now to the drawings and particularly to FIGS. l and 2, aneedle cylinder 1, has an upper rim 3 accommodating the sinkers, abovewhich is arranged the hook platen or dial 5, having a series of groovesfor radially slidable hooks and intended to knit, among other things,so-called automatic welts. The platen 5 rotates synchronously with theneedle cylinder 1. A fixed platform 7 surrounds the needle cylinderbelow the sinkers.

Within the needle cylinder 1 a shaped shell '9 has from the topdownwardly an upper frusto-conical mouth portion 9A, a step 9B, acylindrical portion 9C and further frustoconical portion 9E and tube 9F.The Iknit fabric M produced is unwound and is turned over, in general,by the action of an airstream in the direction of the arrow f1. The knitfabric M extends from the step 9B towards ICC the tube 9F with a lengththereof spaced from the shell 9 corresponding to the portions 9C, 9Ethereof.

:Within the shell 9 a rotary support 10 is secured below the platen 5and forms a seat, for example comprising a pair of wings or flanges. Thesupport 1i) accommodates a shearing device in accordance with theinvention which can be extended through a suitable slot to render itoperative on the length of the fabric lying between the step 9B and thetube 9F, in order to effect shearing during the rotation of the unit andthe forming of the knit fabric.

According to the embodiment shown in FIGS. 1 and 2, the shearing devicetakes the form of a pair of scissors, one blade of which extends with apointed extension to penetrate into the knit fabric. The device includesa blade 14- mounted on a pivot 12 forming an end extension or tip 14Aand having an arm 14B biased counterclockwise by a spring 16 around thepivot 12 to an operative position wherein the extension 14A extends intothe fabric (see FIG. 1). The operative position is dened by a stop 1Sagainst `which the blade 14 rests. A second, oscillatory, shorter blade22 is linked to the blade 14 at 20 and overlies (in the side view) theextension 14A. The blade 22 is biased clockwise about the pivot 2.0 by asmall spring 24 also acting on the blade 14. The blade 22 is connectedby a slot and a pin to a forked head 26, carried by the lower end of arod 2S, and capable of sliding vertically and rotating together with theunit 5, 10. The rod 28 is coaxial with the needle cylinder and with theplaten S, passes through a wide hole in the arm 14B, and has a head 28A,on which a pair of rollers 30, carried by a non-rotary forked lever 32,can act.

The forked lever 32 is linked at 34 to an arm 36A of a support 3d whichis carried by the platform 7. The support 36 forms a guide for a slidemember 38 and on this slide member 38 a block 40 is slidable and thisacts with its own extension 40A on the lever 32. The slide member 38 islowered against the action of an opposing spring 41, by means of aliexible control cable 42, controlled for example by a cam of the drumof a program device T, through a tappet P or other cam follower. Theblock 40 has an extension 40B capable of resting beneath and against theupper rim 3 of the needle cylinder by the action of a spring 44 whichbiases the block 40 upwardly with respect to the slide member 38, whenthe slide member 38 has been raised.

Proled cams 46 underlying the rim 3, during the rotation of the cylinderand when the slide member 38 is raised, act on the extension I40B toimpose an oscillatory or other reciprocal motion on the block 4i), andthrough the extension 40A, a corresponding motion on the lever 32 and onthe head 28A. Consequently the rod 28 is made to reciprocate and thelatter reciprocates the blade 22 in co-operation with the spring 24.This action on the blade 22 only takes place when the slide member 38 ismoved upwardly and thus when the rollers 30 of the lever 32 are loweredand the shearingv device is located in the position shown in FIG. 1,that is in the operative position. Movement to this operative positionis caused by the spring 16, which tends to move the blade assembly 14,14A, 14B in the counterclockwise direction y(as seen in FIGS. 1 and 2)to bring it to rest against the pin 18. Under these conditions, theextension 14A penetrates in the length of the fabric M lying between theportions. 9=B and 9F of the shell, and the fabric slides downwardlyalong the cutting edge formed by the extension 14A and is sheared |bythe oscillation of the blade 22 as the fabric is knitted and while theshearing device is operative. The shearing action begins when theextension 14A is extended and ceases when the extension 14A is retractedinto the interior of the flanged support 10, as shown in Theconfiguration of FIG. 2 is achieved when the slide member 38 is loweredby the return action of the cable 42, against the resistance of thespring 41. With this lowering of the slide member 38, the block 40 isalso lowered and this block loses contact with the rim 3 and with theprofiled cams 46, and therefore ceases to oscillate. The lever 32 ismoved to raise the rollers 38 and the latter, in turn, raise the rod 28and the fork 26 entrains the arm 14B of the blade 1-4 and thereby movesthe blade 14 together with the extension 14A against the bias of thespring 16, from the conguration of FIG. l to the configuration of FIG.2, that is, to the inoperative condition of the shearing device.

Referring now to FIGS. 3 to 5, wherein the same references indicateequivalent members, the flanged support together with a pivot 52(similar to the pivot 12) links a bell crank lever 54, one arm 54A ofwhich is loaded -by a spring 56 so as to hold the lever 54 against astop 58 mounted on one ange of the support 10. From this operativeconfiguration the shearing device may be returned into the inoperativeconfiguration by a rotary hollow rod 68 coaxial with the needle cylinderand with the platen 5. A head l68A of the rod 68 carries the arm 54A andserves to move it in a clockwise direction (as shown in FIG. 3) againstthe action of the spring 56. This raising of the head `68A is effectedby the bifurcated end of a lever 72 acting on the rod 68, the lever 72being pivoted at 74 to a support 76 carried by the fixed platform 7. Themotion of the lever 72 is controlled by a flexible cable or othercontrol member `82, operable similarly to the member `42 of the firstembodiment.

The rod `68 carries, above a plate j68B on which the bifurcated end ofthe lever 72 acts, an electrically insulating block 84 which carries ametal track l84A on which a shoe 86 or other contact, borne by the endof the support arm 76 can act. The metal track `841A is connected to aconductor 88, which is secured (see also FIG. 4) to a terminal screw 90,which latter extends into an insulating block 92, housed in the member54. The terminal screw 90 is electrically connected to an electricalresistance 94 which forms a bridge across the block 92 at the tip-shapedend 54B of the lever 54. The resistance 94 is formed in the upper rearportion of the extension 54B. The circuit is completed through a groundor earth contact formed by the lever S4, the resistance 914, the wire88, the track 84A and by the shoe 86', when the block 84 is lowered, andthen the shoe 86 is in contact with the track 84A, and when the lever 54is in the operational position, that is, With the extension 54Bextending to penetrate through the knit fabric M. When the lever 72 isoperated to raise the unit y68, 84, the shoulder or head 68A moves thelever 54 so as to return the extension 54B into the interior of theflanged support 10, and the block 84 is raised so as to be located withthe insulating portion in alignment with the shoe 86, thus cutting theelectric circuit.

When the device is located in the oper-ational position that is, withthe extension 54B projecting, the fabric M (see in particular FIG. 4)tends to slide along the upper edge of the extension 54B, that is in thedirection of the arrow i, of the FIG. 4, and thus to surround theresistance 94, which cuts or shears the fabric by fusion. The fabricportions bounding the cut or sheared fabric slide along the extension54C of the end of the lever 54, so as to be cooled before returningaccidentally into contact under the lever 54. The knit fabric portionsbounding the cut cannot thus be welded together.

In both embodiments, the knit fabric M, by virtue of the shaping of theshell 9, has a portion of free trajectory where the extensions 14A and54B can penetrate at any instant when this is established by the programdrum to form along a desired length of fabric being formed, the requiredlongitudinal cut of the fabric, the shearing device rotating With theplaten S and synchronously with the needle cylinder.

I claim:

'1. A shearing device for use in a circular knitting machine, saiddevice being capable of producing a longitudinal cut in knit fabricduring the knitting thereof on said machine, said device comprisingsupport means secured below the platen for the hooks and having alateral opening therein facing the needle cylinder at a position atwhich the cut is to be formed,

shearing means mounted on the support means and means operable to movethe shearing means through the said lateral opening between aninoperative position within the support means vand an operative positionat which the cut in the knit fabric is formed.

2. A device according to claim 1, wherein said shearing means comprisesscissors including a lower blade shaped as a hook to assist penetrationof the knit fabric,

an upper blade and means to reciprocate said blades relatively to oneanother.

3. A device according to claim 2, wherein said scissors further includeresilient means biasing the blades to the operative position,

a linkage forming part of said reciprocating means, and acting to stopthe blades when the linkage is actuated to retract the blades to theAinoperative position.

4. A device 'according to claim 1, wherein said shearing means includesan electrical resistance, and

means for cooling the knit fabric after shearing by the resistance.

5. A device according to claim 4, comprising a bell-crank leverreciprocally-mounted within the support means, said resistance beingmounted in one arm thereof,

a hollow vertically-extending rod passing through the other arm of thebell-crank lever, and

a lever reciprocal to actuate the rod vertically and thereby entrain thebell-crank lever.

6. A device according to claim 5, comprising an electrical conductorpassing through the hollow rod to the resistance.

References Cited UNITED STATES PATENTS 960,755 6/ 1910 Wildman 66-1471,048,879 12/ 1912 Raven 66-147 2,411,259 11/ 1946 Gilbreath 66--1472,515,687 7/ 1950 Bausher 66-147 2,543,574 2/ 1951 Gilbreath 66-1472,749,731 6/ 1956 Moser 66-147 2,933,908 4/ 1960 Thore 66-147 2,995,0218/ 1961 Payne et al 66-147 2,995,912 8/1961 Payne et al. 66-1473,218,829 11/ 1965 Seiler 66-147 RONALD FELDBAUM, Primary Examiner

